One of the main methods existing today for extracting oil from plants is solvent-based extraction, in which the plant material containing the extractable compounds is bathed or washed in a solvent. The solvent uptakes the extractable compounds from the plant material and combines the plant material in a solution with the solvent. The compound solution is then purified to remove the solvent and recover the desired extracted compound(s). Often, the purification process involves heating the solution to “boil off” or volatilize the solvent from the solution, leaving the extracted compound(s) behind. Such extraction methods usually use a solvent having a lower boiling point than that of the products so that the solvent can be boiled off without removing or damaging the extracted compound(s).
Existing methods of this type may exhibit low throughput due to bottlenecks at the solvent recovery stage, and frequent process interruptions as solvent is restocked (due to process losses).